Merge branch 'master' into bugfix/2232-adopt-distutils-default

.bumpversion.cfg

 [bumpversion]
-current_version = 49.1.3
+current_version = 49.3.0
 commit = True
 tag = True
 

.github/ISSUE_TEMPLATE/blank.md

----
-name: Bug Report or Feature Request
-about: Report a bug or request a feature
----

.github/ISSUE_TEMPLATE/setuptools-warns-about-python-2-incompatibility.md

----
-name: Setuptools warns about Python 2 incompatibility
-about: Report the issue where setuptools 45 or later stops working on Python 2
-title: Incompatible install in (summarize your environment)
-labels: Python 2
-assignees: ''
-
----
-
-<!--
-
-Please DO NOT SUBMIT this template without first investigating the issue and answering the questions below. This template is intended mainly for developers of systems and not for end users. If you are an end user experiencing the warning, please work with your system maintainers (starting with the project you're trying to use) to report the issue.
-
-If you did not intend to use this template, but only meant to file a blank issue, just hit the back button and click "Open a blank issue".
-
-Setuptools 45 dropped support for Python 2 with a strenuous warning and Setuptools 47 fails to run on Python 2.
-
-In most cases, using pip 9 or later to install Setuptools from PyPI or any index supporting the Requires-Python metadata will do the right thing and install Setuptools 44.x on Python 2.
-
-If you've come to file an issue, it's probably because some process managed to bypass these protections.
-
-Your first course of action should be to reason about how you managed to get an unsupported version of Setuptools on Python 2. Please complete the sections below and provide any other detail about your environment that will help us help you.
-
--->
-
-## Prerequisites
-
-<!-- These are the recommended workarounds for the issue. Please
-try them first. -->
-
-- [ ] Read [Python 2 Sunset docs](https://setuptools.readthedocs.io/en/latest/python%202%20sunset.html).
-- [ ] Python 2 is required for this application.
-- [ ] I maintain the software that installs Setuptools (if not, please contact that project).
-- [ ] Setuptools installed with pip 9 or later.
-- [ ] Pinning Setuptools to `setuptools<45` in the environment was unsuccessful.
-
-## Environment Details
-
-- Operating System and version:
-- Python version:
-- Python installed how:
-- Virtualenv version (if using virtualenv): n/a
-
-Command(s) that triggered the warning/error (and output):
-
-```
-```
-
-Command(s) used to install setuptools (and output):
-
-```
-```
-
-Output of `pip --version` when installing setuptools:
-
-```
-```
-
-## Other notes

.github/workflows/python-tests.yml

@@ -25,23 +25,54 @@ jobs:
         - 3.6
         - 3.5
         os:
-        - ubuntu-latest
+        - ubuntu-18.04
         - ubuntu-16.04
         - macOS-latest
         # - windows-2019
         # - windows-2016
+        include:
+        # Pre-release versions (GH-shipped)
+        - os: ubuntu-20.04
+          python-version: 3.9.0-beta.4 - 3.9.0
+        # Pre-release versions (deadsnakes)
+        - os: ubuntu-20.04
+          python-version: 3.9-beta
+        # Dev versions (deadsnakes)
+        - os: ubuntu-20.04
+          python-version: 3.9-dev
+        - os: ubuntu-20.04
+          python-version: 3.8-dev
 
     env:
       NETWORK_REQUIRED: 1
+      PYTHON_VERSION: ${{ matrix.python-version }}
       TOX_PARALLEL_NO_SPINNER: 1
       TOXENV: python
+      USE_DEADSNAKES: false
 
     steps:
     - uses: actions/checkout@master
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v1.1.1
+    - name: Set flag to use deadsnakes
+      if: >-
+        endsWith(env.PYTHON_VERSION, '-beta') || 
+        endsWith(env.PYTHON_VERSION, '-dev')
+      run: |
+        from __future__ import print_function
+        python_version = '${{ env.PYTHON_VERSION }}'.replace('-beta', '')
+        print('::set-env name=PYTHON_VERSION::{ver}'.format(ver=python_version))
+        print('::set-env name=USE_DEADSNAKES::true')
+      shell: python
+    - name: Set up Python ${{ env.PYTHON_VERSION }} (deadsnakes)
+      uses: deadsnakes/action@v1.0.0
+      if: fromJSON(env.USE_DEADSNAKES) && true || false
+      with:
+        python-version: ${{ env.PYTHON_VERSION }}
+    - name: Set up Python ${{ env.PYTHON_VERSION }}
+      uses: actions/setup-python@v2.1.1
+      if: >-
+        !fromJSON(env.USE_DEADSNAKES) && true || false
       with:
-        python-version: ${{ matrix.python-version }}
+        python-version: ${{ env.PYTHON_VERSION }}
     - name: Log Python version
       run: >-
         python --version
@@ -73,9 +104,9 @@ jobs:
       run: >-
         python -m pip freeze --all
     - name: Adjust TOXENV for PyPy
-      if: startsWith(matrix.python-version, 'pypy')
+      if: startsWith(env.PYTHON_VERSION, 'pypy')
       run: >-
-        echo "::set-env name=TOXENV::${{ matrix.python-version }}"
+        echo "::set-env name=TOXENV::${{ env.PYTHON_VERSION }}"
     - name: Log env vars
       run: >-
         env
@@ -91,6 +122,7 @@ jobs:
         python -m
         tox
         --parallel auto
+        --parallel-live
         --notest
         --skip-missing-interpreters false
     - name: Test with tox
@@ -98,3 +130,6 @@ jobs:
         python -m
         tox
         --parallel auto
+        --parallel-live
+        --
+        -vvvvv

CHANGES.rst

+v49.3.0
+-------
+
+* #2259: Setuptools now provides a .pth file (except for editable installs of setuptools) to the target environment to ensure that when enabled, the setuptools-provided distutils is preferred before setuptools has been imported (and even if setuptools is never imported). Honors the SETUPTOOLS_USE_DISTUTILS environment variable.
+
+
+v49.2.1
+-------
+
+* #2257: Fixed two flaws in distutils._msvccompiler.MSVCCompiler.spawn.
+
+
+v49.2.0
+-------
+
+* #2230: Now warn the user when setuptools is imported after distutils modules have been loaded (exempting PyPy for 3.6), directing the users of packages to import setuptools first.
+
+
 v49.1.3
 -------
 

README.rst

-.. image:: https://raw.githubusercontent.com/pypa/setuptools/master/docs/logo/banner%201%20line%20color.svg
-
-
 .. image:: https://img.shields.io/pypi/v/setuptools.svg
    :target: `PyPI link`_
 
@@ -27,7 +24,6 @@
 .. image:: https://tidelift.com/badges/github/pypa/setuptools?style=flat
    :target: https://tidelift.com/subscription/pkg/pypi-setuptools?utm_source=pypi-setuptools&utm_medium=readme
 
-
 See the `Installation Instructions
 <https://packaging.python.org/installing/>`_ in the Python Packaging
 User's Guide for instructions on installing, upgrading, and uninstalling
@@ -58,4 +54,4 @@ Code of Conduct
 
 Everyone interacting in the setuptools project's codebases, issue trackers,
 chat rooms, and mailing lists is expected to follow the
-`PyPA Code of Conduct <https://www.pypa.io/en/latest/code-of-conduct/>`_.
+`PSF Code of Conduct <https://github.com/pypa/.github/blob/main/CODE_OF_CONDUCT.md>`_.

setuptools/distutils_patch.py → _distutils_hack/__init__.py

-"""
-Ensure that the local copy of distutils is preferred over stdlib.
-
-See https://github.com/pypa/setuptools/issues/417#issuecomment-392298401
-for more motivation.
-"""
-
 import sys
-import re
 import os
+import re
 import importlib
 import warnings
 
 
+is_pypy = '__pypy__' in sys.builtin_module_names
+
+
+def warn_distutils_present():
+    if 'distutils' not in sys.modules:
+        return
+    if is_pypy and sys.version_info < (3, 7):
+        # PyPy for 3.6 unconditionally imports distutils, so bypass the warning
+        # https://foss.heptapod.net/pypy/pypy/-/blob/be829135bc0d758997b3566062999ee8b23872b4/lib-python/3/site.py#L250
+        return
+    warnings.warn(
+        "Distutils was imported before Setuptools. This usage is discouraged "
+        "and may exhibit undesirable behaviors or errors. Please use "
+        "Setuptools' objects directly or at least import Setuptools first.")
+
+
 def clear_distutils():
     if 'distutils' not in sys.modules:
         return
-    warnings.warn("Setuptools is replacing distutils")
+    warnings.warn("Setuptools is replacing distutils.")
     mods = [name for name in sys.modules if re.match(r'distutils\b', name)]
     for name in mods:
         del sys.modules[name]
@@ -40,5 +49,48 @@ def ensure_local_distutils():
     assert '_distutils' in core.__file__, core.__file__
 
 
-if enabled():
-    ensure_local_distutils()
+def do_override():
+    """
+    Ensure that the local copy of distutils is preferred over stdlib.
+
+    See https://github.com/pypa/setuptools/issues/417#issuecomment-392298401
+    for more motivation.
+    """
+    warn_distutils_present()
+    if enabled():
+        ensure_local_distutils()
+
+
+class DistutilsMetaFinder:
+    def find_spec(self, fullname, path, target=None):
+        if path is not None or fullname != "distutils":
+            return None
+
+        return self.get_distutils_spec()
+
+    def get_distutils_spec(self):
+        import importlib.util
+
+        class DistutilsLoader(importlib.util.abc.Loader):
+
+            def create_module(self, spec):
+                return importlib.import_module('._distutils', 'setuptools')
+
+            def exec_module(self, module):
+                pass
+
+        return importlib.util.spec_from_loader('distutils', DistutilsLoader())
+
+
+DISTUTILS_FINDER = DistutilsMetaFinder()
+
+
+def add_shim():
+    sys.meta_path.insert(0, DISTUTILS_FINDER)
+
+
+def remove_shim():
+    try:
+        sys.meta_path.remove(DISTUTILS_FINDER)
+    except ValueError:
+        pass

_distutils_hack/override.py

+__import__('_distutils_hack').do_override()

conftest.py

@@ -15,10 +15,28 @@ collect_ignore = [
     'tests/manual_test.py',
     'setuptools/tests/mod_with_constant.py',
     'setuptools/_distutils',
-    'setuptools/distutils_patch.py',
+    '_distutils_hack',
 ]
 
 
+def pytest_configure(config):
+    disable_coverage_on_pypy(config)
+
+
+def disable_coverage_on_pypy(config):
+    """
+    Coverage makes tests on PyPy unbearably slow, so disable it.
+    """
+    if '__pypy__' not in sys.builtin_module_names:
+        return
+
+    # Recommended at pytest-dev/pytest-cov#418
+    cov = config.pluginmanager.get_plugin('_cov')
+    cov.options.no_cov = True
+    if cov.cov_controller:
+        cov.cov_controller.pause()
+
+
 if sys.version_info < (3,):
     collect_ignore.append('setuptools/lib2to3_ex.py')
     collect_ignore.append('setuptools/_imp.py')

docs/distutils-legacy.txt

+Porting from Distutils
+======================
+
+Setuptools and the PyPA have a `stated goal <https://github.com/pypa/packaging-problems/issues/127>`_ to make Setuptools the reference API for distutils.
+
+Since the 49.1.2 release, Setuptools includes a local, vendored copy of distutils (from late copies of CPython) that is disabled by default. To enable the use of this copy of distutils when invoking setuptools, set the enviroment variable:
+
+	SETUPTOOLS_USE_DISTUTILS=local
+
+This behavior is planned to become the default.
+
+Prefer Setuptools
+-----------------
+
+As Distutils is deprecated, any usage of functions or objects from distutils is similarly discouraged, and Setuptools aims to replace or deprecate all such uses. This section describes the recommended replacements.
+
+``distutils.core.setup`` → ``setuptools.setup``
+
+``distutils.cmd.Command`` → ``setuptools.Command``
+
+``distutils.log`` → (no replacement yet)
+
+``distutils.version.*`` → ``packaging.version.*``
+
+If a project relies on uses of ``distutils`` that do not have a suitable replacement above, please search the `Setuptools issue tracker <https://github.com/pypa/setuptools/issues/>`_ and file a request, describing the use-case so that Setuptools' maintainers can investigate. Please provide enough detail to help the maintainers understand how distutils is used, what value it provides, and why that behavior should be supported.

docs/index.txt

-.. image:: https://raw.githubusercontent.com/pypa/setuptools/master/docs/logo/banner%201%20line%20color.svg
-
-
 Documentation
 =============
 
@@ -18,4 +15,5 @@ Documentation content:
    development
    roadmap
    Deprecated: Easy Install <easy_install>
+   distutils-legacy
    history

docs/logo/README.md

-![](setup_tools_logo_colour.svg)
-### Design:
-
-Setuptools logo designed in 2020 by [C.Rogers](crogersmedia.com) for the Setuptools project using the Free Open Source graphics editor [Inkscape](inkscape.org).
-
-### Copyright:
-Logo is (c) the Setuptools developers.
-
-### Font:
-The font used is the Open Font "Josefin Sans", which is available for free under the Open Font License (OFL).

docs/logo/josefinsans/.uuid

-922c129c-9f4c-4831-b632-c7f43be6feb0
\ No newline at end of file

docs/logo/josefinsans/DESCRIPTION.en_us.html

-<p>
-The idea of this typeface is to be geometric, elegant, with a vintage feeling, for use at larger sizes.
-It is inspired by geometric sans serif designs from the 1920s.
-The x-height is half way from baseline to cap height, an unusual proportion.
-</p>
-<p>
-There is a sister family, <a href="https://fonts.google.com/specimen/Josefin+Slab">Josefin Slab</a>
-</p>
-

docs/logo/josefinsans/METADATA.pb

-name: "Josefin Sans"
-designer: "Santiago Orozco"
-license: "OFL"
-category: "SANS_SERIF"
-date_added: "2010-11-17"
-fonts {
-  name: "Josefin Sans"
-  style: "normal"
-  weight: 100
-  filename: "JosefinSans-Thin.ttf"
-  post_script_name: "JosefinSans-Thin"
-  full_name: "Josefin Sans Thin"
-  copyright: "Copyright 2010 The Josefin Sans Project Authors (https://github.com/ThomasJockin/JosefinSansFont-master), with Reserved Font Name \"Josefin Sans\"."
-}
-fonts {
-  name: "Josefin Sans"
-  style: "italic"
-  weight: 100
-  filename: "JosefinSans-ThinItalic.ttf"
-  post_script_name: "JosefinSans-ThinItalic"
-  full_name: "Josefin Sans Thin Italic"
-  copyright: "Copyright 2010 The Josefin Sans Project Authors (https://github.com/ThomasJockin/JosefinSansFont-master), with Reserved Font Name \"Josefin Sans\"."
-}
-fonts {
-  name: "Josefin Sans"
-  style: "normal"
-  weight: 300
-  filename: "JosefinSans-Light.ttf"
-  post_script_name: "JosefinSans-Light"
-  full_name: "Josefin Sans Light"
-  copyright: "Copyright 2010 The Josefin Sans Project Authors (https://github.com/ThomasJockin/JosefinSansFont-master), with Reserved Font Name \"Josefin Sans\"."
-}
-fonts {
-  name: "Josefin Sans"
-  style: "italic"
-  weight: 300
-  filename: "JosefinSans-LightItalic.ttf"
-  post_script_name: "JosefinSans-LightItalic"
-  full_name: "Josefin Sans Light Italic"
-  copyright: "Copyright 2010 The Josefin Sans Project Authors (https://github.com/ThomasJockin/JosefinSansFont-master), with Reserved Font Name \"Josefin Sans\"."
-}
-fonts {
-  name: "Josefin Sans"
-  style: "normal"
-  weight: 400
-  filename: "JosefinSans-Regular.ttf"
-  post_script_name: "JosefinSans-Regular"
-  full_name: "Josefin Sans Regular"
-  copyright: "Copyright 2010 The Josefin Sans Project Authors (https://github.com/ThomasJockin/JosefinSansFont-master), with Reserved Font Name \"Josefin Sans\"."
-}
-fonts {
-  name: "Josefin Sans"
-  style: "italic"
-  weight: 400
-  filename: "JosefinSans-Italic.ttf"
-  post_script_name: "JosefinSans-Italic"
-  full_name: "Josefin Sans Italic"
-  copyright: "Copyright 2010 The Josefin Sans Project Authors (https://github.com/ThomasJockin/JosefinSansFont-master), with Reserved Font Name \"Josefin Sans\"."
-}
-fonts {
-  name: "Josefin Sans"
-  style: "normal"
-  weight: 600
-  filename: "JosefinSans-SemiBold.ttf"
-  post_script_name: "JosefinSans-SemiBold"
-  full_name: "Josefin Sans SemiBold"
-  copyright: "Copyright 2010 The Josefin Sans Project Authors (https://github.com/ThomasJockin/JosefinSansFont-master), with Reserved Font Name \"Josefin Sans\"."
-}
-fonts {
-  name: "Josefin Sans"
-  style: "italic"
-  weight: 600
-  filename: "JosefinSans-SemiBoldItalic.ttf"
-  post_script_name: "JosefinSans-SemiBoldItalic"
-  full_name: "Josefin Sans SemiBold Italic"
-  copyright: "Copyright 2010 The Josefin Sans Project Authors (https://github.com/ThomasJockin/JosefinSansFont-master), with Reserved Font Name \"Josefin Sans\"."
-}
-fonts {
-  name: "Josefin Sans"
-  style: "normal"
-  weight: 700
-  filename: "JosefinSans-Bold.ttf"
-  post_script_name: "JosefinSans-Bold"
-  full_name: "Josefin Sans Bold"
-  copyright: "Copyright 2010 The Josefin Sans Project Authors (https://github.com/ThomasJockin/JosefinSansFont-master), with Reserved Font Name \"Josefin Sans\"."
-}
-fonts {
-  name: "Josefin Sans"
-  style: "italic"
-  weight: 700
-  filename: "JosefinSans-BoldItalic.ttf"
-  post_script_name: "JosefinSans-BoldItalic"
-  full_name: "Josefin Sans Bold Italic"
-  copyright: "Copyright 2010 The Josefin Sans Project Authors (https://github.com/ThomasJockin/JosefinSansFont-master), with Reserved Font Name \"Josefin Sans\"."
-}
-subsets: "latin"
-subsets: "latin-ext"
-subsets: "menu"
-subsets: "vietnamese"

docs/logo/josefinsans/OFL.txt

-Copyright (c) 2010, Santiago Orozco (hi@typemade.mx)
-
-This Font Software is licensed under the SIL Open Font License, Version 1.1.
-This license is copied below, and is also available with a FAQ at:
-http://scripts.sil.org/OFL
-
-
------------------------------------------------------------
-SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
------------------------------------------------------------
-
-PREAMBLE
-The goals of the Open Font License (OFL) are to stimulate worldwide
-development of collaborative font projects, to support the font creation
-efforts of academic and linguistic communities, and to provide a free and
-open framework in which fonts may be shared and improved in partnership
-with others.
-
-The OFL allows the licensed fonts to be used, studied, modified and
-redistributed freely as long as they are not sold by themselves. The
-fonts, including any derivative works, can be bundled, embedded, 
-redistributed and/or sold with any software provided that any reserved
-names are not used by derivative works. The fonts and derivatives,
-however, cannot be released under any other type of license. The
-requirement for fonts to remain under this license does not apply
-to any document created using the fonts or their derivatives.
-
-DEFINITIONS
-"Font Software" refers to the set of files released by the Copyright
-Holder(s) under this license and clearly marked as such. This may
-include source files, build scripts and documentation.
-
-"Reserved Font Name" refers to any names specified as such after the
-copyright statement(s).
-
-"Original Version" refers to the collection of Font Software components as
-distributed by the Copyright Holder(s).
-
-"Modified Version" refers to any derivative made by adding to, deleting,
-or substituting -- in part or in whole -- any of the components of the
-Original Version, by changing formats or by porting the Font Software to a
-new environment.
-
-"Author" refers to any designer, engineer, programmer, technical
-writer or other person who contributed to the Font Software.
-
-PERMISSION & CONDITIONS
-Permission is hereby granted, free of charge, to any person obtaining
-a copy of the Font Software, to use, study, copy, merge, embed, modify,
-redistribute, and sell modified and unmodified copies of the Font
-Software, subject to the following conditions:
-
-1) Neither the Font Software nor any of its individual components,
-in Original or Modified Versions, may be sold by itself.
-
-2) Original or Modified Versions of the Font Software may be bundled,
-redistributed and/or sold with any software, provided that each copy
-contains the above copyright notice and this license. These can be
-included either as stand-alone text files, human-readable headers or
-in the appropriate machine-readable metadata fields within text or
-binary files as long as those fields can be easily viewed by the user.
-
-3) No Modified Version of the Font Software may use the Reserved Font
-Name(s) unless explicit written permission is granted by the corresponding
-Copyright Holder. This restriction only applies to the primary font name as
-presented to the users.
-
-4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
-Software shall not be used to promote, endorse or advertise any
-Modified Version, except to acknowledge the contribution(s) of the
-Copyright Holder(s) and the Author(s) or with their explicit written
-permission.
-
-5) The Font Software, modified or unmodified, in part or in whole,
-must be distributed entirely under this license, and must not be
-distributed under any other license. The requirement for fonts to
-remain under this license does not apply to any document created
-using the Font Software.
-
-TERMINATION
-This license becomes null and void if any of the above conditions are
-not met.
-
-DISCLAIMER
-THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
-MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
-OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
-COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
-INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
-DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
-FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
-OTHER DEALINGS IN THE FONT SOFTWARE.

setup.cfg

@@ -16,7 +16,7 @@ formats = zip
 
 [metadata]
 name = setuptools
-version = 49.1.3
+version = 49.3.0
 description = Easily download, build, install, upgrade, and uninstall Python packages
 author = Python Packaging Authority
 author_email = distutils-sig@python.org
@@ -72,6 +72,7 @@ tests =
     paver; python_version>="3.6"
     futures; python_version=="2.7"
     pip>=19.1 # For proper file:// URLs support.
+    jaraco.envs
 
 docs =
     # Keep these in sync with docs/requirements.txt

setup.py

@@ -5,8 +5,10 @@ Distutils setup file, used to install or test 'setuptools'
 
 import os
 import sys
+import textwrap
 
 import setuptools
+from setuptools.command.install import install
 
 here = os.path.dirname(__file__)
 
@@ -81,8 +83,48 @@ def pypi_link(pkg_filename):
     return '/'.join(parts)
 
 
+class install_with_pth(install):
+    """
+    Custom install command to install a .pth file for distutils patching.
+
+    This hack is necessary because there's no standard way to install behavior
+    on startup (and it's debatable if there should be one). This hack (ab)uses
+    the `extra_path` behavior in Setuptools to install a `.pth` file with
+    implicit behavior on startup to give higher precedence to the local version
+    of `distutils` over the version from the standard library.
+
+    Please do not replicate this behavior.
+    """
+
+    _pth_name = 'distutils-precedence'
+    _pth_contents = textwrap.dedent("""
+        import os
+        var = 'SETUPTOOLS_USE_DISTUTILS'
+        enabled = os.environ.get(var, 'local') == 'local'
+        enabled and __import__('_distutils_hack').add_shim()
+        """).lstrip().replace('\n', '; ')
+
+    def initialize_options(self):
+        install.initialize_options(self)
+        self.extra_path = self._pth_name, self._pth_contents
+
+    def finalize_options(self):
+        install.finalize_options(self)
+        self._restore_install_lib()
+
+    def _restore_install_lib(self):
+        """
+        Undo secondary effect of `extra_path` adding to `install_lib`
+        """
+        suffix = os.path.relpath(self.install_lib, self.install_libbase)
+
+        if suffix.strip() == self._pth_contents.strip():
+            self.install_lib = self.install_libbase
+
+
 setup_params = dict(
     src_root=None,
+    cmdclass={'install': install_with_pth},
     package_data=package_data,
     entry_points={
         "distutils.commands": [

setuptools/__init__.py

 """Extensions to the 'distutils' for large or complex distributions"""
 
-import os
+from fnmatch import fnmatchcase
 import functools
+import os
+import re
 
-# Disabled for now due to: #2228, #2230
-import setuptools.distutils_patch  # noqa: F401
+import _distutils_hack.override  # noqa: F401
 
 import distutils.core
-import distutils.filelist
-import re
 from distutils.errors import DistutilsOptionError
 from distutils.util import convert_path
-from fnmatch import fnmatchcase
 
 from ._deprecation_warning import SetuptoolsDeprecationWarning
 

setuptools/_distutils/_msvccompiler.py

@@ -15,7 +15,9 @@ for older versions in distutils.msvc9compiler and distutils.msvccompiler.
 
 import os
 import subprocess
-import winreg
+import contextlib
+with contextlib.suppress(ImportError):
+    import winreg
 
 from distutils.errors import DistutilsExecError, DistutilsPlatformError, \
                              CompileError, LibError, LinkError
@@ -501,7 +503,7 @@ class MSVCCompiler(CCompiler) :
             log.debug("skipping %s (up-to-date)", output_filename)
 
     def spawn(self, cmd):
-        env = dict(os.environ, path=self._paths)
+        env = dict(os.environ, PATH=self._paths)
         return super().spawn(cmd, env=env)
 
     # -- Miscellaneous methods -----------------------------------------

setuptools/_distutils/ccompiler.py

@@ -906,8 +906,8 @@ int main (int argc, char **argv) {
     def execute(self, func, args, msg=None, level=1):
         execute(func, args, msg, self.dry_run)
 
-    def spawn(self, cmd):
-        spawn(cmd, dry_run=self.dry_run)
+    def spawn(self, cmd, **kwargs):
+        spawn(cmd, dry_run=self.dry_run, **kwargs)
 
     def move_file(self, src, dst):
         return move_file(src, dst, dry_run=self.dry_run)

setuptools/_distutils/tests/test_msvccompiler.py

@@ -2,6 +2,7 @@
 import sys
 import unittest
 import os
+import threading
 
 from distutils.errors import DistutilsPlatformError
 from distutils.tests import support
@@ -74,6 +75,42 @@ class msvccompilerTestCase(support.TempdirManager,
         else:
             raise unittest.SkipTest("VS 2015 is not installed")
 
+
+class CheckThread(threading.Thread):
+    exc_info = None
+
+    def run(self):
+        try:
+            super().run()
+        except Exception:
+            self.exc_info = sys.exc_info()
+
+    def __bool__(self):
+        return not self.exc_info
+
+
+class TestSpawn(unittest.TestCase):
+    def test_concurrent_safe(self):
+        """
+        Concurrent calls to spawn should have consistent results.
+        """
+        import distutils._msvccompiler as _msvccompiler
+        compiler = _msvccompiler.MSVCCompiler()
+        compiler._paths = "expected"
+        inner_cmd = 'import os; assert os.environ["PATH"] == "expected"'
+        command = ['python', '-c', inner_cmd]
+
+        threads = [
+            CheckThread(target=compiler.spawn, args=[command])
+            for n in range(100)
+        ]
+        for thread in threads:
+            thread.start()
+        for thread in threads:
+            thread.join()
+        assert all(threads)
+
+
 def test_suite():
     return unittest.makeSuite(msvccompilerTestCase)
 

setuptools/monkey.py

@@ -138,7 +138,7 @@ def patch_for_msvc_specialized_compiler():
     msvc = import_module('setuptools.msvc')
 
     if platform.system() != 'Windows':
-        # Compilers only availables on Microsoft Windows
+        # Compilers only available on Microsoft Windows
         return
 
     def patch_params(mod_name, func_name):

setuptools/sandbox.py

@@ -185,8 +185,8 @@ def setup_context(setup_dir):
     temp_dir = os.path.join(setup_dir, 'temp')
     with save_pkg_resources_state():
         with save_modules():
-            hide_setuptools()
             with save_path():
+                hide_setuptools()
                 with save_argv():
                     with override_temp(temp_dir):
                         with pushd(setup_dir):
@@ -195,6 +195,15 @@ def setup_context(setup_dir):
                             yield
 
 
+_MODULES_TO_HIDE = {
+    'setuptools',
+    'distutils',
+    'pkg_resources',
+    'Cython',
+    '_distutils_hack',
+}
+
+
 def _needs_hiding(mod_name):
     """
     >>> _needs_hiding('setuptools')
@@ -212,8 +221,8 @@ def _needs_hiding(mod_name):
     >>> _needs_hiding('Cython')
     True
     """
-    pattern = re.compile(r'(setuptools|pkg_resources|distutils|Cython)(\.|$)')
-    return bool(pattern.match(mod_name))
+    base_module = mod_name.split('.', 1)[0]
+    return base_module in _MODULES_TO_HIDE
 
 
 def hide_setuptools():
@@ -223,6 +232,10 @@ def hide_setuptools():
     necessary to avoid issues such as #315 where setuptools upgrading itself
     would fail to find a function declared in the metadata.
     """
+    _distutils_hack = sys.modules.get('_distutils_hack', None)
+    if _distutils_hack is not None:
+        _distutils_hack.remove_shim()
+
     modules = filter(_needs_hiding, sys.modules)
     _clear_modules(modules)
 

setuptools/tests/requirements.txt

@@ -10,3 +10,4 @@ pytest-cov>=2.5.1
 paver; python_version>="3.6"
 futures; python_version=="2.7"
 pip>=19.1 # For proper file:// URLs support.
+jaraco.envs

setuptools/tests/test_distutils_adoption.py

+import os
+import sys
+import functools
+import subprocess
+import platform
+
+import pytest
+import jaraco.envs
+import path
+
+
+IS_PYPY = '__pypy__' in sys.builtin_module_names
+
+
+class VirtualEnv(jaraco.envs.VirtualEnv):
+    name = '.env'
+
+    def run(self, cmd, *args, **kwargs):
+        cmd = [self.exe(cmd[0])] + cmd[1:]
+        return subprocess.check_output(cmd, *args, cwd=self.root, **kwargs)
+
+
+@pytest.fixture
+def venv(tmpdir):
+    env = VirtualEnv()
+    env.root = path.Path(tmpdir)
+    env.req = os.getcwd()
+    return env.create()
+
+
+def popen_text(call):
+    """
+    Augment the Popen call with the parameters to ensure unicode text.
+    """
+    return functools.partial(call, universal_newlines=True) \
+        if sys.version_info < (3, 7) else functools.partial(call, text=True)
+
+
+def find_distutils(venv, imports='distutils', env=None, **kwargs):
+    py_cmd = 'import {imports}; print(distutils.__file__)'.format(**locals())
+    cmd = ['python', '-c', py_cmd]
+    if platform.system() == 'Windows':
+        env['SYSTEMROOT'] = os.environ['SYSTEMROOT']
+    return popen_text(venv.run)(cmd, env=env, **kwargs)
+
+
+def test_distutils_stdlib(venv):
+    """
+    Ensure stdlib distutils is used when appropriate.
+    """
+    assert venv.name not in find_distutils(venv, env=dict()).split(os.sep)
+
+
+def test_distutils_local_with_setuptools(venv):
+    """
+    Ensure local distutils is used when appropriate.
+    """
+    env = dict(SETUPTOOLS_USE_DISTUTILS='local')
+    loc = find_distutils(venv, imports='setuptools, distutils', env=env)
+    assert venv.name in loc.split(os.sep)
+
+
+@pytest.mark.xfail('IS_PYPY', reason='pypy imports distutils on startup')
+def test_distutils_local(venv):
+    """
+    Even without importing, the setuptools-local copy of distutils is
+    preferred.
+    """
+    env = dict(SETUPTOOLS_USE_DISTUTILS='local')
+    assert venv.name in find_distutils(venv, env=env).split(os.sep)

tox.ini

@@ -27,10 +27,6 @@ extras =
 	tests
 
 
-[testenv:pypy{,3}]
-commands = pytest --no-cov {posargs}
-
-
 [testenv:coverage]
 description=Combine coverage data and create report
 deps=coverage